Clinical diagnostic analyzers are being developed with increasing levels of complexity and sophistication in order to fully automate the performance of chemical assays and immunoassays of biological fluid samples such as urine, blood serum, plasma, cerebrospinal liquids and the like, these fluid samples almost universally being contained in open or capped sample tubes. Generally, chemical reactions between an analyte in a patient's biological sample and reagents used during performing the assay result in generating various signals that can be measured by the analyzer. From these signals the concentration of the analyte in the sample may be calculated.
A wide variety of automated chemical analyzers are known in the art and are continually being improved to increase analytical menu and throughput, to reduce turnaround time, and to decrease requisite sample volumes. See for example, U.S. Pat. Nos. 6,103,193, and 6,027,691 and 5,482,861. Such improvements, while necessary in themselves, may be hampered if sufficient corresponding advances are not made in the automation of pre-analytical sample preparation and handling operations like sorting, batch preparation, centrifugation of sample tubes to separate sample constituents, cap removal to facilitate fluid access, and the like.
Automated clinical sample treatment and transportation systems generally include conveyor systems for conveying specimens to processing stations, such as those described in U.S. Pat. Nos. 6,060,022, and 5,972,295. Typical of such systems, a sample is transported to an analyzer by a primary conveyor and shuttled onto an analyzer-specific buffer lane that transports samples to the sampling area of an adjacent analyzer in the order in which they were placed. A problem with such systems arises when an incoming sample has a higher priority for testing than samples already on the primary conveyor or already in the processing station-specific buffer lane. One solution is to control the conveyor so that all samples preceding the higher priority are forced to by-pass the target processing station and/or to move the samples already in the specific buffer lane back onto the primary conveyor in order to allow the higher-priority sample to be processed without further delay. Both of these solutions are undesirable since the overall throughput of the sample handling treatment and transportation system is reduced when samples are inefficiently passed more than once around the primary conveyor.
U.S. Pat. No. 7,011,792 discloses an automatic analyzing apparatus having a plurality of analyzer units for serum, blood plasma and urine arranged along a main transfer line for transferring a sample rack from a rack providing portion to an analyzer specific sampling lane to a rack storage area. Each newly added sample follows a previously added sample on the main transfer line and/or within the analyzer specific sampling lanes. In the event of a high-priority sample, samples are forwarded directly to the analyzer unit at which the operation priority is assigned, however it is not clear how one sample on the main transfer line can by-pass another.
U.S. Pat. No. 6,290,907 discloses a sample handling system with a transportation line for transporting a sample rack, a rack loading device for loading the transportation line, a rack storage device for storing the sample rack transported by the transportation line, a plurality of treating units for treating samples held in a sample rack. The transportation line includes pairs of plural partitive line units and treating units. In the case of high-priority samples, an operator sets such samples at an emergency sample mounting position and are provided with priority over normal sample racks in a normal sample mounting areas. Again, the high-priority samples are not given priority over samples already on the transportation line nor over sample racks buffered in the sample processing area of an analyzer.
U.S. Pat. No. 6,060,022, automatically presents pre-treated samples in open containers to robotic devices operated in conjunction with independent stand-alone analyzers. No special provision is made for high-priority samples.
U.S. Pat. No. 5,972,295 discloses an automatic analyzing apparatus having a rack supply unit and a transfer line for transferring a sample rack supplied from the rack supply unit to a sampling position within an analyzing unit. An emergency (high-priority) sample input unit is provided so that the high-priority sample rack can be placed at the entrance of the conveying line giving priority over ordinary sample racks in the rack supply unit. However, the high-priority sample rack is not given priority over sample racks already on the conveying line nor over sample racks buffered in the sample processing area of an analyzer.
Although these prior art systems have advanced the art of sample handling and processing, what has not been addressed is the challenge of enabling samples to be presented to a processing station from the conveyor in a prioritized, independent order without delays from other samples scheduled to be processed by the same processing station.